There are 90 infringement procedures open against Spain, the EU's 30th Annual Report on monitoring the application of EU law reveals.
That's a number topped only by Italy, which is still dealing with 99 cases, and Belgium which has 92 ongoing cases.
At the other end of the scale was Latvia, with only 20 open cases. The other Baltic States of Lithuania and Estonia were the other top performers.
The environment, transport, taxation, and the internal market and services were the thorniest areas, making up a full 60 percent of those open files.
Spain also scored badly for new complaints in 2012 with 306 new complaints being filed against the EU member state.
Italy came first with 438 complaints and France third with 242.
As was the case in 2011, the lion's share of complaints from citizens, businesses and organizations concerned the environment, justice and internal market and services (588, 491 and 462 complaints, respectively).
But the overall picture is one of less naughtiness and more compliance. Overall, there were 25 percent fewer infringements open at the end of 2012 than in previous years.
The EU put this down to an increased reliance on two new IT-based dispute resolution and problem solving tools.
The European Commission has the power to sue member states for infringements of rules at the European Court of Justice and demand financial penalties.